Flat Plate Exchanger hookup question

[Handysmrf]

Hello All,
I'm new here and looking for advice.
When I hook up my OWB to the plate exchanger (not tube!) which is ultimately connected to the hot water heater. Will it thermosiphon effectively or will I need a pump? (to circulate the water heater side)
Some folks say it will thermosiphon OK and others say a pump is necessary.
I need max heat transfer, which I think would save on wood usage.
Logic steers me towards the pump.
Anyone...?

 

[iCreek]

Do you have a seperate loop coming from the OWB to circulate water through this water to water plate exchanger? If so I would think a pump would be the best way to guarantee water flow, thus heating your cold water that is passing through the plate against the hot water. Just my 2 cents worth.

Mine us hooked in line, and I have gone down to the utility room and actually felt the 'hot' PEX going to the water heater, and the PEX has been cold. So I know it does take water circulating, my pump runs on demand, to guarantee hot water on the other side of the plate exchangers it might be best to run the pump 24/7.. Another new thread talking about the pumps running 24/7....

http://www.arboristsite.com/showthread.php?t=76341

Hopefully some others will chime in..... ps. Welcome to the AS forums.

 

[Handysmrf]

Thanks for the welcome and reply iCreek!
I think you've said enough when the "hot" is cold to the touch.
One other factor may be the connection to the water heater and whether it's connected from the bottom drain to the pressure relief valve port. Maybe it would thermosiphon then?
How's yours connected?

 

[iCreek]

How's yours connected?

Mine is connected from the top, I flow the heated water in where I normally flow cold water in, I have a ball value for the off season. It is the connection right in the middle of this picture, the ball value is closed as we just finished soldering and have not cut over when I took this pic. The blue PEX is the cold water going to the water to water plate exchanger.

 

[Butch(OH)]

I am no expert but I have never seen a plate type heater installation that would thermosyphon. Are you are thinking about hanging it on the side of the water heater like a tube? If so I dont think it will work. The plate heats are designed to be force fed by both circuits, boiler and domestic. Another way to say it is in 'series". Was an excellant drawing posted here a week or two ago in another thread.

 

[iCreek]

Was an excellant drawing posted here a week or two ago in another thread.

Here is that thread, scroll down and you will see the post and the drawing.
credit to Madspeed
http://www.arboristsite.com/showthread.php?t=75889

 

[Madspeed]

I just try to do my homework before coming to class!!:computer:

 

[abohac]

Hello All,
I'm new here and looking for advice.
When I hook up my OWB to the plate exchanger (not tube!) which is ultimately connected to the hot water heater. Will it thermosiphon effectively or will I need a pump? (to circulate the water heater side)
Some folks say it will thermosiphon OK and others say a pump is necessary.
I need max heat transfer, which I think would save on wood usage.
Logic steers me towards the pump.
Anyone...?

I don't know if this is what your saking but I have a Grundfos pump at my stove (300 ft from house) and it pushes water from the stove to the plate exchanger, to two different forced air furnances and back to the stove. Works very well.